The formation of stars, galaxies, and the large-scale structure in the Universe drives complex energy density flows over a wide range of scales from atomic nuclei to the Hubble length. The net effect could be summarized by a census of the density parameters, Ω, for different entries in the cosmic inventory over time. I will present my ongoing effort to probe the history of several key cosmic constituents, including stars, dust, thermal, and gravitational energy associated with the large-scale structure. To do so, we deproject the cosmic UV, IR, and the Sunyaev-Zeldovich effect backgrounds over redshift using a new tomographic intensity mapping approach. While the results are already pushing our understanding of the Universe, they represent only the beginning of a new chapter of cosmology and astrophysics using the entire radiation field as opposed to only bright, individually detectable galaxies. Looking forward, I will describe the infrastructure that we are building and highlight some exciting science opportunities in the next decade.